FTIR DETECTION OF AN ENZYME-BOUND ORGANOMETALLIC CARBONYL PROBE IN THE PRESENCE OF THE UNBOUND PROBE MOLECULE

High-frequency shoulders on nu(s)(CO) and nu(as)(CO) bands in the FTIR spectra of an organometallic probe derived from tricarbonyl(1-4-eta-5-pyridiniocyclohexa-1,3-diene)iron hexafluorophosphate have been observed on incubation with alpha-chymotrypsin and were assigned to an iron complex covalently bonded to enzyme-NH2 groups; curve-fitting analysis of the spectra enabled the bound complex to be detected even in the presence of an excess of the unbound probe and its FTIR spectrum to be calculated and compared with spectral data arising from similar interactions between the tricarbonyliron moiety and 12 amino acids and polylysine.